Difference between an implementation and an interface

Question

In OLE DB, what is the difference between an implementation and an interface?

Answer 1

An OLE DB interface is specified through a set of objects, and the technique and properties that they expose, and OLE DB describes standardized interfaces. An object need not expose all of its functions and techniques in a given interface. An OLE DB implementation describes how the object supports the interface. The implementation is entirely hidden from the user. Therefore developers of an object are free to change the implementation when they want, however they should not change the interface without consulting their users.